Dissecting cell composition and drug sensitivity in human adenoid cystic carcinomas (ACCs).

腺样囊性癌（ACC）是最常见且具有生物侵袭性的形式之一 唾液腺上皮恶性肿瘤，目前还没有临床批准的治疗方法。ACCS 其特征在于高度倾向于神经周围浸润和远处转移，并且在很大程度上 对常规的化学-放射疗法方法是难治的。ACC也由一种独特的生物学特性定义， 功能：恶性组织内两种表型不同的癌细胞亚群共存 （导管样与肌上皮样），其特征在于深刻不同的基因表达谱和功能 特性.这项研究将利用我们实验室最近确定的一系列表面标志物， 首次允许这两种细胞类型的差异纯化、分子研究和功能分析。 本研究正式检验的假设是：a）两种细胞类型以动态和分层的方式共存 平衡，其中一种细胞类型作为另一种细胞类型的祖细胞发挥功能;和B）生物化学途径 调节一种细胞类型向另一种细胞类型的转化可以用来开发新的治疗方法 针对ACC。该项目设想了两个具体目标：1）阐明发展关系 ACC的两种细胞成分之间的差异：我们将使用荧光激活细胞分选术（FACS）， 从人ACC中纯化两个癌细胞亚群，然后采用前瞻性的体内研究， 异种移植实验和单细胞RNA-seq技术来测试两种细胞类型是否： 在患者来源的异种移植物（PDX）中显示出肿瘤引发能力的稳健和系统性差异 来自独立患者的线; B）是分层相关的（即两者是否可以可塑性地相互转化为 彼此或是否一个以单向方式充当另一个的祖先）; c）包含 另外，以前未被识别的细胞亚群，其本身以不同的分子和 功能特性; 2）测试新型药物组合的体外和体内治疗功效 针对ACC，旨在靶向显示影响差异表达的生化途径 和两种细胞亚型的优先存活：我们将治疗3D类器官和PDX细胞系， 概括了具有顺序药物方案的原代ACC的双细胞组成，在第一步中， 诱导肌上皮样细胞分化为导管样细胞，并且在第二步中，选择性地 消除导管样细胞;这种新的药物方案将测试它们的能力：a）引起 恶性组织的细胞组成（导管/肌上皮细胞比率）; B）减小肿瘤大小和/或生长动力学; c）防止体内转移性播散（使用非侵入性生物发光报道分子）。意义这 这项研究将阐明在人类ACC中发现的两种细胞类型的分子和功能特性，填补了 唾液腺肿瘤生物学的重大科学空白，并解决唾液腺肿瘤学未满足的临床需求： 确定药物治疗ACC的新药物靶点。

Adenoid Cystic Carcinomas (ACCs) represent one of the most common and biologically aggressive forms of epithelial malignancy of the salivary glands, for which there are no clinically approved treatments. ACCs are characterized by a high tendency towards peri-neural infiltration and distant-site metastasis, and are largely refractory to conventional chemo-radiotherapy approaches. ACCs are also defined by a distinctive biological feature: the co-existence within malignant tissues of two phenotypically distinct sub-populations of cancer cells (ductal-like vs. myoepithelial-like) characterized by profoundly distinct gene-expression profiles and functional properties. This study will leverage a portfolio of surface markers recently identified by our laboratory that allow, for the first time, the differential purification, molecular study and functional analysis of these two cell types. The hypotheses formally tested by this study are: a) that the two cell types co-exist in a dynamic and hierarchical equilibrium, whereby one cell type functions as a progenitor for the other; and b) that biochemical pathways regulating the conversion of one cell type into the other can be leveraged to develop new therapeutic approaches against ACCs. The project envisions two specific aims: 1) to elucidate the developmental relationship between the two cellular components of ACCs: we will use fluorescence activated cell sorting (FACS) to purify the two sub-populations of cancer cells from human ACCs, and then employ prospective in vivo xenotransplantation experiments and single-cell RNA-seq technologies to test whether the two cell types: a) display robust and systematic differences in tumor-initiating capacity across patient-derived xenograft (PDX) lines from independent patients; b) are hierarchically related (i.e. whether both can plastically inter-covert into each other or whether one serves as the progenitor of the other, in a mono-directional fashion); c) contain additional, previously unrecognized cellular sub-populations, themselves characterized by distinct molecular and functional properties; 2) to test the in vitro and in vivo therapeutic efficacy of novel drug combinations against ACCs, designed to target biochemical pathways shown to affect the differential representation and preferential survival of the two cellular sub-types: we will treat 3D organoids and PDX lines shown to recapitulate the dual cell composition of primary ACCs with sequential drug regimens, designed to, in a first step, induce the differentiation of myoepithelial-like cells into ductal-like cells and, in a second step, to selectively eliminate ductal-like cells; such novel drug regimens will be tested for their capacity to: a) cause changes in the cell composition of malignant tissues (ductal/myoepithelial cell ratio); b) reduce tumor size and/or growth kinetics; c) prevent in vivo metastatic dissemination (using non-invasive bio-luminescent reporters). Significance. This study will elucidate the molecular and functional properties of the two cell types found in human ACCs, filling a major scientific gap in salivary tumor biology, and addressing an unmet clinical need in salivary gland oncology: the identification of novel drug targets for the pharmacological treatment of ACCs.